Last Updated on March 13, 2023 by Marsh Fasteners
Curious about why the use of stainless steel fasteners in marine and coastal applications is a common practice? Then you’re in the right place! Let’s dive in and find out.
What Makes Marine Conditions So Harsh?
At the best of times, you want fasteners that contribute to the safety, longevity, low maintenance, and cost-effectiveness of your structures. But in harsh environments these criteria are harder to achieve.
Conditions specific to coastal areas and marine structures put materials to the test and include:
- Use in different zones – marine atmosphere, splash, tidal, full immersion, and mud zones.
- Exposure to a combination of corrosive chemicals, for example chlorides in seawater and brackish water. Corrosive chemicals can cause pitting, crevice corrosion, intergranular corrosion, and stress corrosion cracking.
- High salt concentrations in the air and in seawater or sea spray leads to faster corrosion because of the increased presence of dissolved ions.
- Extreme temperatures affect the integrity of materials.
- Vibrations and dynamic loads can cause metal fatigue.
What Stainless Steel is Suitable?
Marine grade fasteners are designed to withstand the demanding conditions listed above. Stainless steel fasteners offer the following benefits:
- Exceptional resistance to corrosion.
- Durable and strong – even in drastic temperature fluctuations.
- The ability to be easily and effectively welded.
But not all stainless steel is created equal. The amount of chromium in the alloy has to be at least 10.5% in stainless steel. But that alone is insufficient in marine applications. By choosing incorrect grades of stainless steel you could find your fastener suffering from crevice corrosion, stress corrosion, pitting and cracking.
Stainless steel for the above water coastal conditions must be austenitic grades 1.4401, 1.4404, or 1.4542.
For submerged joints you want A4 or 316 grade with a minimum of 6% molybdenum in the alloy.
Since 1992, Marsh Fasteners has been the go-to fastener suppliers for the marine and coast construction industries. From screws, bolts, threaded rods, nuts, washers, nails, deck screws, sockets, and carriage cap nuts, to anchoring systems, rivets, pins, eye bolts, turnbuckles, hose clamps, u-bolts, and more, our range is quite extensive and always growing.
If you are looking for something specific or need assistance in finding a suitable product for the job at hand – including the best-quality stainless steel fasteners – please contact us today!